Sheet feeder



May 4, 1943 c. w. HARRQLDv 2,317,993

SHEET FEEDER Filed March 15, 1941 5 Sheets-Sheet 1 T h/ F7' coMA/EcrfaT0 05555/5601? 774,055

INV ENTO cH/amfsw Hama ATTORNEY 5 May 4, 1943 c. w. HARROLD SHEET FEEDERFiled March 15, 1941 5 Sheets-Sheet 2 NTOR.

. INVE CHHLES V HH ATTORNEY` May 4, 1943. c. w. HARROLD SHEET FEEDERFiled March 15. 1941 5 Sheets-Sheet 3 May 4, 1943.

C. W. HARROLD SHEET FEEDER Filed March l5, 1941 5 Sheets-Sheet 4INVENTOR.

CHHRLES. M HHIWOLD BY 15M f/Wfw ATTORNEY5 -May 4, 1943.

C. W. HARROLD SHEET FEEDER Filed March 15, 1941 5 Sheets-Shea?l 5 N-INVENTOR www g wf #@Wwm@ BY fm #M1/Mz ATTORNEY Patented May 4, 19432,317,993 g SHEET FEEDER `Charles W. Harrold, University Heights, Ohio,assigner to Harris-Seybold-Potter Company, Cleveland, Ohio, acorporation oi Delaware Application March 15, 1941, Serial No. 383,576

30 Claims.

This invention relates to improvements in sheet feeders, and hasreference particularly to novel mechanism for assuring the presentationof individual sheets at the proper time and in accurately registeredposition to a machine for operating upon them, such as a printing press.

In feeding relatively large sheets of paper or the like to a printingpress it is customary to separate the sheets individually from a pile orother supply and convey them, either in fully separated condition orpartially overlapping one another, along a feed board to a so-calledregistering position where they are stopped and brought into accurateregistration with the press, from which position they are taken by thepress and printed.

One method of registration which has found wide acceptance consists inbringing the sheet against two front stops or guides located on oppositesides of the center of the sheet and a side guide located along one sideedge, this method being known as three-point register.

A difficulty experienced in carrying out this method is that sheets ofheavy stock have a tendency to rebound after striking the stops andsheets of light or imsy stock have a tendency to buckle thus impairingthe registration of the sheets. vThis is true even when the sheets arefed relatively slowly in overlapping relation, particularly in respectto the buckling of light stocks, because of the force exerted by thesucceeding underlying sheets upon the foremost sheet when it engages thestops.

A further diiiiculty lies in the fact that the sheets may be improperlyintroduced into the conveying mechanism by the devices which separatethem from the supply, so that they are slightly displaced forward orbackward from their proper position or are slightly askew so that theirfront edges are not exactly at right angles to the direction ofmovement. Such irregularities must be eliminated before or during theregistering operation. In particular, when lapped sheets are askewconsiderable registering time is consumed in straightening them owing tothe slow travel of the sheets.

It also occasionally occurs that a sheet is so far out of position inthe conveyor that it cannot be properly registered, or that no sheet isfed, and under such circumstances it is necessary to stop the printingoperation and the feeding of sheets until the difliculty is corrected.

Various mechanisms have been contrived for overcoming these difficultiesand carrying out the desired functions, but in most instances suchmechanisms are only partially eective or are complicated and difficultto maintain in proper adjustment.

Accordingly one of the objects of this invention is to provide improvedmechanism capable of performing some or all of the functions of slowingdown, straightening, timing, registering and detecting the presence orabsence of sheets being fed in succession to a printing or othermachine.

Another object is to provide mechanism of the character stated whichshall be simple in construction and eflicient and durable in operation.

Another object is to provide mechanism of the character stated lin whichsuction is 'employed for carrying out certain of the functions.

Another object is to provide a suction device especially adapted to slowa sheet down without itself having bodily movement, the slowingdowneiect being brought about by the gradual closing of the sucker orificeby the moving sheet.

A further object is to provide mechanism of the character stated whichis especially adapted to operate upon sheets fed in lapped condition.

Still another object is to provide a device wherein suction is employedto slow down a moving sheet and the presence or absence of a sheet atthe sucker mouth governs the continuance i or the discontinuance of thefeeding operation.

Other objects and features of novelty will appear as I proceed with thedescription of those embodiments of the invention which, for thepurposes of the present application, I have illustrated in theaccompanying drawings, in which- Fig. 1 is a side elevational view ofdiagrammatic character with certain parts in vertical section, on theline l-I of Fig. 3, illustrating one embodiment of the invention.

Fig. 2 is a view similar to Fig. 1 but with the parts in a differentposition corresponding to a different point in the operating cycle.

Fig. 3 is a diagrammatic end elevational view partly in section on theline 3 3 of Fig. 1.

Fig. 4 is a fragmental plan view taken substantially on the line 4-4 ofFig. 1.

Fig. 5 is a fragmental detail sectional view taken substantially on theline 5-5 of Fig. 1.

Fig. 6 is a fragmental plan view showing an askew sheet as it approachesthe registering position.

Figs. 7 and 8 are fragmental plan views simila to Fig. 4 illustratingthe slowing down and registering of a sheet.

Fig. 9 is a vertical sectional view of the sucker head on the line 9-9of Fig. 4.

Fig. 10 is a vertical sectional view of the sucker head on line Ill-I6of Fig. 9.

Figs. 11, 12 and 13 are fragmental vertical sectional views illustratingmodified forms of the invention.

In the drawings one end of a sheet conveyor of known design isillustrated comprising tapes I trained around a roller Il which isjournaled in the frames F of the machine. Idler wheels I2 are employedto press the sheets against the tapes to insure proper forwardingaction. The sheets, illustrated at Si, S2 and S3 are successivelyprojected by the tapes onto a feed board or plate I3 and into engagementwith the slow-down, registering and detecting devices hereafter to bedescribed. Adjacent the forward end of the feed board is a fed-in deviceof known design comprising a shaft 4 upon which are mounted a pluralityof arms I5 which support gripper contact bar |6 and gripper pivot shaftI1. Upon bar I6 are secured a plurality of sheet guides I8 and upon eachend of pivot shaft I1 is an arm I9 which supports an end of grippershaft which carries grippers 2 I.

'I'his feed-in device is operated in any suitable manner and by anysuitable known mechanism to transfer `the sheets one at a time from thefeed board I3 to the grippers (not shown) of a sheet handling cylinder22 which may be the constantly rotating impression cylinder of aprinting press. Preferably, however, the feed-in device is driventhrough one full rotation for each sheet fed thereto, and each cycle ofrotation comprises a, stationary period during which the sheet isgripped by grippers 2 I, as shown in Fig. 2,

slows down to a stop preparatory to taking the next sheet. Mechanism ofthis kind is shown and described in Patent No. 2,192,908, issued March12, 1940.

Preferably also the gripper shaft 20 and grippers 2| are actuated byknown mechanism to swing about pivot shaft I1 within the path defined bybar I6 during the decelerating period so as to clear a sheet lyingwholly or partly on the feed board I3. When the feed-in device isstopped shaft 20 and grippers 2| swing outward to their operativepositions and the grippers are closed on the sheet.

In the preferred form of the invention, illus- 'trated in Figs. 1 to 10,inclusive, front registering guides 23 are provided which are mounted inthe usual way upon a rock shaft 24 journaled in the frames F. Shaft 24is oscillated by known mechanism not shown to move the guides 23 fromtheir operative position shown in solid lines to their inoperativeposition shown in dotted lines in Fig. 2. At least two such guides 23are used, one

on each side of the center of the machine, and I prefer to use fourarranged in pairs as shown for purposes which will appear.

Between the members of each pair of guides 23 the front portion of thefeed board I3 is notched out as at 24' to provide clearance for theupper ends of arms 25 which are rotatably mounted on rock shaft 26. Eacharm 25 is bifurcated at its lower end and between the bifurcations andkeyed to shaft 26 is a dog 21 having two parallel upstanding extensions28, 29 between which a transverse wall portion 30 of arm 25 extends. Acoil spring 3| carried in a hole in Wall 3D bears against extension 29of dog 21 and an adjusting screw 32 in extension 28 of dog 21 bearsagainst wall 30, thus yieldably and adjustably holding arm 25 in desiredangular relation to shaft 26.

Rock shaft 26 is journaled in a plurality of arms 33, 34 that are fixedto a rigid cross brace 35 carried in frames F. Arm 34 is formed with anear 36 that is drilled to receive loosely a rod 31 having an eye at itsopposite end which rotatably receives a pin 38 carried in one arm of abell crank lever 39 which is locked to shaft 26. Between the ear 36 anda collar 40 secured to rod 31 is a coil spring 4| which tends to rotatethe bell crank lever 39 andv consequently the shaft 26 counter-clockwiseas viewed in Figs. 1 and 2.

'I'he other arm ofbell crank lever 35iV carries a pin 42 which pivotallysupports one end of a bar 43 whose other end is bifurcated and arrangedto be slidably supported on block 44 loosely carried on rotating shaft45. Bar 43 carries a stud 46 on which is mounted a roller 41 which runson a cam 48 keyed to shaft 45, the roller being pressed against the camby the action of spring 4|.

Shaft 45 is rotatably journaled in the frames F and is driven with onerotation for each sheet fed along the feed board I3. By means of theconnections described, cam 48 therefore acts to swing arms 25 fromoperative position shown in Fig. 1 to inoperative position shown in Fig.2 with similar periodicity.

Each arm 25 comprises at its upper end a block 49 formed on its underside to t in a groove 50 in the body of the arm and secured thereto by ascrew 5I. Each block 49 is formed with an abutment 52 adapted to engagethe front edges of the sheets and the upper surface of the block on theside of abutment 52 toward the feed board is arranged to liesubstantially in the plane of the upper surface of feed board I3 whenthe block is in its operative position within the notches 24'.

Block 49 is provided with a hole 53 whose upper end is counterbored toreceive a cylindrical plug 54 having a hole 55 connecting with hole 53.The upper end of plug 54 is formed into a series of slots 56 connectingwith hole 55 and separated by bars 51. 'I'he cylindrical plug isarranged with one edge substantially coincident with abutment 52 and theslots 56 and bars 51 are arranged with their longest dimensions in thedirection of movement of the sheets.

This slotted plug forms the mouth of a sheet gripping sucker, and whilethe particular formation of the same herein illustrated is preferred, itwill be understood that variations in the shape and arrangement of theplug and passages therethrough may be adopted without departing from thespirit of the invention.

The body of arm 25 is provided with passage 58 which connects hole 53with a passage 59 whosev outer end is sealed by plug 60 and whose innerend connects with a vertical passage 6|.

The lower end of passage 6| communicates with a transverse cylindricalchamber (see Fig. 5) which has two sections, first a section 62 arrangedto receive a plunger 63, and second a section 64 arranged to receive acompression spring 65 surrounding the shank 66 of plunger 63. The spring65 is confined between the shoulder 61 of plunger 63 and bottom 68 ofchamber section 84 and tends to push plunger 63 outwardinto the positionshown-in Fig. 5. Shank 66 extends with a close sliding fit through abore 69 in the arm 25 and is threaded to receive a nut 10 which limitsthe extent of movement of the plunger to the left. Chamber 62 is of suchdepth as to permit plunger 63 to be drawn entirely into the chamber,movement in the latter direction being limited by shoulder 1|.

Arm 25 is further provided with a passage 12 leading from chamber 64 toa hollow elbow 13 to which is attached one end of a hose 14. The twohoses 14 leading from the two arms are connected to nipples 15 each ofwhich communicates with a common chamber 16 in bracket 11 secured uponrock shaft 26 approximately centrally 0f the machine. Chamber 16 isconnectedy by a single nipple 18 and hose 19 to a source of suction.

Although under some circumstances suction may be applied to the suckermouths 54 continuously during operation of the machine, I prefer tocontrol the suction so that it is applied only during those portions ofthe working cycle when the sucker mouth is required to grip a sheet. Forthis purpose I have illustrated diagrammaticaily a valve between hose 19and a further hose connection 80 which leads to a source of suction suchas a suction pump (not shown). This valve comprises a stationary casing8| and rotary plug 82 therein having a suction passage 83 and a bleedpssage 84, the latter operating to connect opening 85 in casing 8| withthe hose 19 leading to the sucker mouths when suction is cut off. Therotary plug 82 is turned through an angle by arm 86 connected to a rod81 which is oscillated by a cam or other suitable mechanism (not shown)in time with the movements of arms 25. Preferably the timing is suchthat suction at the sucker mouths 54 is applied just before the frontedge of each sheet moving along the feed board arrives at the suckermouth and is cut off immediately after arms 25 have traveled towardtheir Fig. 2 position sufficiently to carry the sucker mouths 54completely past the front guides 23.

From the preceding description it is apparent that when air issumciently exhausted from chamber 62, 64, atmospheric pressure againstthe outer end of plunger 63 will force the latter completely within thechamber against the resistance of spring 65, and that under all otherconditions plunger 63 will remain in its outer position. It

is also apparent that when suction is applied to i hose 19 the pressurecondition within chamber 62, 64 depends upon whether or not the suckermouth openings 56 are closed, or partially closed by a sheet.

The operation of the sheet separating and forwarding devices iscontrolled in accordance with the position of plunger 63 by mechanism offamiliar character which will now be described briefly. A shaft 88 isprovided which extends across the feeder and is oscillatably journaledin the frames F. This shaft corresponds to the trip control shaftcommonly found in sheet feeding mechanism. Near one end of shaft 88 iskeyed an arm 89 carrying a roller 90 which runs on a cam 9| keyed to thecontinuously rotating shaft 45, the roller being resiliently biasedtoward the cam by a spring 92 secured to arm 89 and to a pin 83 at asuitable point of thel frame. Cam 9| is formed to produce oneoscillation of shaft 88 during each revolution of shaft 45 at a. time tobe later indicated.

On shaft 88 arms 84 are keyed in proper position laterally of themachine to engage Dlungers 63, each of the arms being formed with aplunger engaging pad 85.

The position of shaft 88 at certain times in the cycle of operationv isutilized to control the operation of conveyor tapes l0 and preferablyalso other parts of the feeding mechanism including the devices by whichthe sheets are fed to the conveyer tapes l0. The means for accomplishingthis result are not shown since they are well known (for example see U.S. Patent No. 2,200,367, dated May 14, 1940), and are not per se a partof this invention. The arrangement is such, however, that so long asoscillation of shaft 88 under the influence of cam 9| is permitted,tapes I0 and shaft 45 continue to operate, and when oscillation of shaft88 is prevented, as by contact of one of the arms 94 with thecorresponding plunger 63, the tapes |0 and shaft 45 are stopped, thuscausing discontinuance of the feed of sheets to the grippers 2|.

It is to be noted that the formation of the sucker mouth is such that amoving sheet, as its front edge passes over the sucker, gradually closesthe slots 56 to atmosphere while being effectively supported by the bars51 against being drawn down into the sucker mouth. When the source ofsuction is connected, as by the valve 82, this gradual closing of thesucker mouths of the sheet causes a gradual exhaustion of air within thesuction passages with the result that the sheet is pressed progressivelymore firmly against bars 51 and the surrounding supporting surfaces byatmospheric pressure. Such progressive increase in pressure in turncauses a progressive increase in the force of friction between the sheetand its supporting surfaces opposing the forces which are moving thesheet forward. Thereby the sheet is effectively slowed down as it movesacross the sucker mouth toward the abutment 52. Preferably the degree ofexhaustion obtainable when the sucker mouth is completely closed ischosen in relation to the forces tending to drive the sheet forward sothat the sheet is very nearly but not quite completely slowed down tostationary condition at the time it reaches abutment 52, but this is notcritical and the suction may under some conditions properly be strongenough to stop the sheet completely before it reaches the abutment,since for final registration the sheet is pulled forward against guides23 by the suckers.

The slowing down action of the sucker mouths is illustrated in Fig. 7wherein the dash lines indicate successive positions occupied by thefront edge of a sheet S after successive equal intervals of time duringwhich the sheet is being acted upon by the uniformly moving conveyortapes |0. It is seen that the front edge of the sheet comes to restagainst the abutment 52 only after the greater part of its momentum hasbeen dissipated by the slowing down effect of the sucker mouth.

It is further to be noted that in the form illustrated the forwardingeffect of the tapes I0 and any underlying sheets is transmitted to theforemost sheet by frictional contact and that therefore slippage mayoccur therebetween as the foremost sheet is slowed down by the suckermouths. Such slippage is proper and in the case of stiff sheets is quitenecessary. It is also apparent, however, that in the case of thinflexible sheets positive forwarding devices near the rear of the sheetcould be employed and the sheet allowed to buckle in its termedlateregions to compensate for the slo g down of the front edge.

After the sheet is slowed down and stopped against abutments 52, suctionis preferably maintained for a time and the arms 25 are relativelyslowly moved toward inoperative position to draw the sheet gently upagainst the registering guides 23 and to draw the sucker mouthsgradually off the sheet so as to urge the latter firmly but gentlyagainst the guides. This action is illustrated in Fig. 8 in which theslots 56 are shown partially uncovered by the withdrawal of the suckermouth from the stationary sheet. It is seen that the sheet is firsturged i'lrmly against the guides 23 by the full force of the frictionbetween the sheet and the face of the sucker mouth and then held in thatposition with gradually decreasing force as the suction is broken bygradual uncovering of the sucker. 'I'his gradual release of the sheet isimportant since some deformation and strains exist in the sheet near theguides owing to its pressure thereagainst which if allowed to besuddenly corrected by the natural resiliency of the sheet may cause thesheet to spring back away from the guides. Such distortion and` strainsin the sheet are also minimized by the arrangement of the guides 23 inpairs, one on each side of a sucker, as shown.

In addition to the simple slowing down of the front edge of the sheet, asheet straightening action is effected by the arrangement of the twosucker mouths at some distance apart on opposite sides of the center ofthe sheet and by the proper positioning of the idler wheels I2.

As illustrated in Fig. 6 the wheels I2 are placed at a distance backfrom the abutments 52 such that they will act on a sheet to forward itsubstantially into contact with abutments 52 and will thereafter exertno appreciable forwarding action thereon. One wheel is placed on each Yside of the center of the sheet and preferably substantially in linewith the corresponding abutment 52. 'I'he action of each wheel isindependent of the other owing to the frictional connection between thesheet andthe tapes. Thus as atwisted sheet approaches the front end ofthe feed board one side engages its sucker and is slowed downtherebywhile the other side continues its more rapid forward movement until itin turn engages its sucker and is slowed down thereby. In this way arapid squaring up of the sheet is attained.

The operation of the preferred form of the invention above described maybe summarized as follows.

With arms 25 and guides 23 in the positions shown in Fig. l and suctionon" so that air is being sucked in through slots 56, the tapes I0 andwheels I2 advance the foremost sheet into engagement with sucker mouths54. As the sheet gradually covers slots 56, atmospheric pressure on thesheet causes increased frictional resistance to its forward travel withthe result that the sheet slows down prior to reaching abutments 52,slippage meanwhile taking place between tapes I0 and the sheet. Thesheet is also straightened as it is slowed down. 'Ihe closing of slots56 causes plungers 83 to withdraw into chambers 62 out of the path ofarms 84. At the moment when a properly advanced sheet would close slots66 sufficiently to cause withdrawal of under roller causing spring 82 totend to oscillate shaft 88 clockwise and raise arms 84 to their dottedline position. If both plungers 63 are withdrawn, arms 84 are free tomove up and shaft 88 oscillates thus permitting the tapes I0 and shaft45 to continue to run. If for any reason the sheet does not cover theslots 56, one or both of the plungers 63 remains extended and interfereswith hte movement of arms 84 thus preventing oscillation of shaft 88 andcausing the tapes I0 and shaft 45 to stop thus stopping further feedingof sheets. After a properly advanced sheet is stopped against abutments52, arms 25 move in the direction oflsheet travel under the influence ofcam 48, such movement being slow in comparison to the speed of the sheetalong board I3, to bring the sheet against front guides 23. Arms 25continue their forward movement. the sheet meanwhile being held on thefeed board by guides 23. After sucker mouths 54 have been drawn of! thesheet suction is cut off by valve 82, and arms 25 continue theirmovement to inoperative position shown in Fig. 2. As soon as the sheethas been properly laid against front guides 23 and the sucker mouths 54have been withdrawn the sheet is side registered preparatory to beingtaken into the machine. Grippers 2| then close upon the sheet, as inFig. 2, guides 23 thereafter move down out of the path of the sheet, andshaft I4 rotates to carry the sheet onto cylinder 22. Immediately afterthe tail of the sheet passes off feed board I3, arms 25 and guides 23are returned to their operative positions to receive the next sheet andthe operations are repeated.

In a modication of the invention shown in Fig. 1l, two sucker mouths I0|(corresponding to mouths 54 in the preferred form of Figs. 1 to 10) arecarried by two arms |02 mounted on an oscillating shaft |03 close underthe feed board. Abutments |04 are provided. corresponding to abutments52. Sucker mouths |0I are connected by tubes |05 and hoses |06 to acommon source of controlled suction. This form operates in a mannersimilar to the form of Figs. 1 to 10 except as follows:

When a sheet has been advanced over the slowing down suckers I 0| andinto contact with abutments |04, suction is then cut off from thesuckers, arms |02 are lowered to carry abutments |04 below the level offeed board I3 and the sheet is advanced into contact with guides 23 -bythe conveyor tapes. Preferably abutments |04 stop the sheet only aslight distance from guides 23 so that the sheet acquires very littlemomentum before reaching the latter guides.

In another form of the invention, -illustrated in Fig. l2 only one setof sheet stops is employed. Front registering guides |01, preferably twoin number, are used and preliminary stops are omitted. Guides |0'I areformed integrally with guide brackets |08 which also are provided withsuction passages |09 leading from the sucker mouths I I 0 (similar tosucker mouths 54) to tubes I II which are connected by hose connectionsI I2 to a controlled source of suction. In the operation of this formthe sheet is fed by the conveyor tapes down table I3 and across suckermouths I I0 with suction on and substantially into contact with guides|01, the sheet being slowed down by the suction effect as it approachessaid guides. At the proper moment in the cycle after the sheet isstopped suction is cut off and the sheet allowed to adjust itselfagainst guides |01, meanwhile beplungers 63 the low part of cam 9|begins to pass 76 ing urged forward to some extent by the conveyortapes. At the proper time the grippers 2I grip the registered sheet andshaft 24 is oscillated to drop guides I 01 out of the way.

In still another form illustrated in Fig. 13 the sucker mouths 54 arenxed in relation to the feed board II3 and preferably are a slightdistance up the feed board fromfront guides 23 as shown. The suckermouths 54 are supportedin blocks I I4 held by screws -II5 to the lbottomof the feed board. Tubes I I6 and hose connections III connect thesource of suction to the suckers. In this form the sheets are sloweddown, straightened without the use of preliminary stops or abutmentssuch as 52 or |04. At the proper moment in the cycle after the sheet isstopped, suction is cut of and the sheet is advanced through a slightdistance to guides 2-3 by the conveyor tapes.

When the invention is employed in connection with sheets fed in lappedrelation it is preferred in some cases, as when very long sheets are tobe fed, to return arms 25 and guides 23 to their operative positions andto advance the next sheet into engagement therewith while the tailportion of the sheet being transferred to cylinder 22 still partlycovers said next sheet. This condition is illustrated in dash lines inFig. 1 wherein SO is the sheet being transferred. It will .be noted thatthe arrangement and location of the sucker mouths 54, abutments 52 andguides 23 underneath the stream of underlapped sheets is especiallyadapted to provide effective operation on the forward edges of thesheets while they are still partly covered. The arrangement of therotary transfer device herein described on the opposite side of thesheet path likewise contributes to this result. It is within theinvention also to arrange the devices so that each sheet is acted uponby the suckers 54 while covered by the preceding sheet and is drawn upagainst the guides 23 only after being uncovered.

Having thus described my invention, I claim:

1. In sheet feeding mechanism, a feed board adapted to support a sheet,a sucker adjacent the front end of said feed board adapted to act uponthe front portion of a sheet for slowing it down, means for advancing asheet along said feed board to carry its front edge across the mouth ofsaid sucker while suction is maintained therein to thereby close thesucker and cause the same to act upon the sheet, and means for cuttingoif suction thereafter to permit registration of the sheet.

2. In sheet feeding mechanism, a feed board adapted to support a sheet,a sucker adjacent the front end of said feed board adapted to act uponthe front portion of a sheet, and means for advancing a sheet along saidfeed board to carry its front edge across the mouth of said sucker whilesuction is maintained therein to thereby close the sucker and cause thesame to act upon the sheet, the advancing sheet being slowed down duringpsage of its front edge across said mouth by frictional resistanceapplied to the surface thereof by virtue of the suction in said sucker.

3. In sheet feeding mechanism, a feed board adapted to support a sheetin a position of rest, a sucker adjacent the front end of said feedboard ,adapted while stationary relative to the feed board to act uponthe front portion of a sheet, and means for advancing a sheet along saidfeed board toward said position of rest to carry its front edge acrossthe mouth of said sucker while said sucker is substantially stationaryand while suction is maintained therein to thereby close vand stoppedentirely by the suction effect and sheet being slowed down duringpassage of its front edge across said mouth by frictional resistanceapplied to the surface thereof by |virtue of the suction in said sucker.

4. In sheet feeding mechanism, a feed board adapted to supporta sheet,two suckers adjacent the frontend of said feed board Vone on each sideof the center of the feed board adapted to act upon the front portion ofa sheet for slowing it down, means for advancing a sheet along said feedboard to*y carry its front edge 'across the mouths of said suckers whilesuction is maintained therein to thereby close said suckers and causethe same to act upon the sheet, and means for cutting oif suctionthereafter to permit registration of the sheet.

5. In sheet feeding mechanism, a feed board for supporting a sheet, asheet registering guide adjacent the front endt of said feed board,means for advancing a sheet along said feed board toward said guide, anda sucker associated with said guide adapted to have its mouth graduallyclosed by the front portion of an advancing sheet as it approaches saidguide, suction being maintained in said sucker during the closingthereof, the sheet being slowed down by frictional resistance induced bythe suction prior to reaching said guide.

6. In sheet feeding mechanism, a feed board for supporting a sheet, twosheet registering guides adjacent the front end of said feed board oneon each side of the center of the feed board, means for advancing asheet along said feed board toward said guides, and a sucker associatedwith each of said guides adapted to have its mouth gradually closed bythe front portion of an advancing sheet as it approaches said guides,suction being maintained in said suckers during closing of the mouthsthereof, each side of the sheet being slowed down substantiallyindependently of the other side by frictional resistance induced by saidsuction prior to reaching the guide on that side.

7. In sheet feeding mechanism, a feed board for supporting a sheet, twosheet registering guides one on each side of the center of the feedboard, means for advancing a sheet along said feed board toward saidguides, two movable suckers one associated with each of said guides. andmeans for moving said suckers into and out of operative position and formaintaining the same substantially stationary for a time in operativeposition, said suckers being adapted in op.

erative position to have their mouths gradually closed by an advancingsheet as it approaches said guides, suction being maintained during theclosing of said mouths, whereby the sheet is slowed down by frictionalresistance as it approaches said guides.

8. In a sheet feeder, front registering guides, suction slow-down meansadapted to act upon the forward edge of a sheet as it approaches thefront guides, and trip means controlled by the suction condition in saidslow-down means for actuation of the trip in the event that a sheetfails to arrive at the slow-down means at the proper time.

9. Ina sheet feeder, front registering guides,

' sucker means having a mouth adjacent the sheet path rearwardly of saidguides, said means being adapted to slow down a sheet as the front edgethereof travels across the sucker mouth toward said guides, and tripmeans controlled by the suction condition in said slow-down means forthe sucker mouth by the sheet, the advancing actuation of the trip inthe event that a sheet fails to close the sucker mouth at the propertime.

10. In a sheet feeder, front registering guides, a sucker beneath thesheet path rearwardly of said guides adapted to slow down a sheet as thefront edge thereof passes over the sucker toward the guides, and tripmeans controlled by the suction condition in said sucker for actuation of the trip in the event that a sheet fails to cover said sucker at theproper time.

11. In a sheet feeder, a feed board adapted to support a sheet, frontregistering guides, a sucker mounted below the sheet path having asucker mouth adjacent said path, whereby the sucker mouth is closed by asheet advancing toward said guides, and means for moving the suckerforward beyond said guides, whereby the guides strip the sheet from thesucker.

12. In a sheet feeder, front registering guides, means for moving saidguides into and out of the sheet path, a sucker arm mounted below thesheet path having a sucker mouth adjacent said path, said sucker mouthbeing adapted to slow down a sheet as it passes thereover in a forwarddirection, trip means controlled by the suction condition in saidslow-down means for actuation of the trip in the event that a sheetfails to close the sucker mouth at the proper time, and means for movingthe sucker arm forward beyond said front guides whereby the guides stripthe sheet from the sucker.

13. In a sheet feeding machine, a sheet de-` tectJr comprising a suckerhaving a sucker mouth adjacent the path of travel of the sheets, asuction line connected with said sucker, means for making suctioneffective therein as a sheet approaches the sucker, said sucker mouthbeing adapted to be closed by the front edge of the sheet as it passesthereover, and means controlled by the pressure condition in said linefor tripping the machine when a sheet fails to close said sucker mouthat the proper time.

14. In a sheet feeding machine, a sheet detector comprising a suckerhaving a sucker mouth adjacent the path of travel of the sheets, asuction line connected with said sucker, means for making suctioneiective therein as a sheet approaches the sucker, said sucker mouthbeing adapted to be closed by the front edge of the sheet as it passesthereover, means for tripping the machine effective at a predeterminedpoint in each cycle, and means made effective by the building up ofsuction in the line as the sheet closes the suction mouth for disablingsaid tripping means.

15. In a sheet feeding machine, sheet slowdown means comprising a suckeradjacent the sheet path having a sucker mouth elongated in the directionof travel of the sheets, and means for making suction effective in saidsucker mouth as the front edge of each sheet approaches the sucker,whereby the sucker mouth is closed gradually by the sheet itself and thespeed of travel of the sheet is decreased.

16. In a sheet feeding machine, sheet slowdown means comprising a suckeradjacent the sheet path, said sucker having a mouth with an effectivelongitudinal dimension greater than its effective transverse dimension,and means for making suction effective in said sucker mouth as the frontedge of the sheet approaches the sucker, whereby the sucker mouth isclosed gradually by the sheet itself and the speed of travel of thesheet is decreased.

17. In sheet lfeeding mechanism, a feed board adapted to support asheet, a pair of sheet registering guides adjacent the fron-t end ofsaid feed board one on each side of the center thereof, a preliminarysheet stop associated with each of said guides adapted to occupy aposition slightly to the rear of said guides, means for advancing asheet along said feed board toward said stops, a sucker associated witheach of said stops adapted to have its mouth graduauy closed by thefront portion of an advancing sheet as it approaches said stops, suctionbeing maintained in said sucker during the closing thereof, each side ofthe sheet being slowed down substantially independently of the otherside thereof by frictional resistance induced by the suction prior toreaching the guide on that side, and means for simultaneouslywithdrawing said stops from operative position in timed relation to therest of the feeding mechanism after a sheet has reached both of saidstops for permitting the sheet to advance to said sheet registeringguides.

18. In sheet feeding mechanism, a feed board adapted to support a sheet,a sheet registering guide adjacent the front end of said feed board, apreliminary sheet stop adapted to occupy a position slightly to the rearof said guide, means for advancing a sheet along said feed board towardsaid stop, a sucker associated with said stop adapted to have its mouthgradually closed by the front portion of an advancing sheet as itapproaches said stop. suction being maintained in said sucker during theclosing thereof, the sheet being slowed down by frictional resistanceinduced by the suction prior to reaching said stop, and means forwithdrawing said stop from operative position in timed relation to therest of the feeding mechanism for permitting the sheet to advance tosaid sheet registering guide.

19. In sheet feeding mechanism, a feed board adapted ,to support asheet, a sucker adjacent the front end of said feed board adapted to actupon the front portion of a sheet, and means including a conveyor tapeand associated sheet hold-down Wheel substantially in line with saidsucker for advancing a sheet by frictionally applied force along saidfeed board to carry the front edge of the sheet across the mouth of saidsucker Iwhile suction is maintained therein to thereby close the suckerand cause the same to slow down the sheet.

20. In sheet feeding mechanism, a feed board adapted to support a sheet,two sheet registering guides adjacent the front end of said feed boardone on each side of the center of the feed board, means including a pairof conveyor tapes and associated sheet hold-down wheels for advancing asheet by frictionally applied force along said feed board toward saidguides, each tape being arranged substantially in line with one of saidguides and the wheel associated therewith being located slightly morethan the length of a sheet away from the corresponding guide, and asucker associated with each of said guides adapted to have its mouthgradually closed by the front portion of a sheet as it approaches saidguides, suc; tion being maintained in said suckers during closing of themouths thereof to thereby slow the sheet down, each side of the sheetbeing acted upon substantially independently of the other side by saidadvancing means and said suckers `whereby the sheet is straightened andslowed down prior to reaching said guides.

21. 'I'he method of slowing down a moving sheet comprising the step ofapplying to the surface of the sheet a gradually increasing frictionalforce opposing the movement of the sheet, the application of said forcebeing controlled in accordance with the position of a transverse edge ofsaid moving sheet.

22. The method of slowing down a moving sheet comprising the step ofapplying to the surface of the front portion of the sheet a graduallyincreasing frictional force opposing the movement of the sheet, theapplication of said force being controlled in accordance with theposition of the front edge of said moving sheet.

23. The method of slowing down a moving sheet comprising the step ofapplying to the surface of the front portion of the sheet a graduallyincreasing frictional force opposite in direction to the movement of thesheet, the rate of increase of said force being controlled in accordancewith the travel of the sheet after the slowing down begins.

l24. The method of slowing down and straightening a moving sheetcomprising the step of applying to the surface of the front portion ofthe sheet at points on opposite sides of the center thereof a graduallyincreasing frictional force opposing the movement of the sheet, theapplication of said force at each of said points being controlled inaccordance with the position of that portion of the front edge of saidmoving sheet adjacent the corresponding point.

25. The method of slowing down and straightening a moving sheetcomprising the step of applying to the surface of the front portion ofthe sheet at points on opposite sides of the center thereof a graduallyincreasing frictiional force opposing the movement of the sheet, therate of increase of said force at each of said points being controlledin accordance with the travel of that portion of the front edge of saidmoving sheet which is adjacent the corresponding point after the slowingdown begins.

26. The method of advancing sheets toward the front guides of a printingpress or other machine comprising applying frictional force to thesurface of a sheet to advance the same, appfying to the surface of thefront portion of the sheet a gradually increasing frictional forceopposing said advancing force to slow the sheet down, the

. application of said opposing force being controlled the surface of thefront portion of the sheet agradually increasing frictional forceopposing said advancing force to slow the sheet down, the application ofsaid opposing force being controlled in accordance with the position ofthe front edge of said 'moving sheet, stopping the `sheet after it isslowed down, and thereafter applying frictional force to the surface ofthe sheet to advance the sheet at reduced speed into engagement withsaid guides. y

28. The method of advancing a sheet to the front guides of a printingpress or other machine comprising advancing the sheet toward the guides,applying to the surface of the front portion of the advancing sheet agradually increasing frictional force opposing the movement of the sheetto slow the latter down prior to reaching said guides, advancing thesheet at reduced speed into engagement with said guides, and holding thesheet in engagement with said guides for a time by gradually decreasingfrictional force applied Y in the direction of sheet advance to thefront portion of the sheet.

29. 'I'he method as claimed in claim 28 wherein is also included thestep of stopping the sheet for a time after it is slowed down4 andbefore it is advanced into engagement with the guides.

30. The method as claimed in claim 28 wherein are included the steps ofcontrolling said increasing and decreasing frictional forces inaccordance with the position of the front edge of the sheet.

CHARLES W. HARROLD.

